Record spindle driving device



Nov. 17, 1942. a PROCTOR 2,302,503

RECORD SPINDLE DRIVING DEVICE Filed Oct. 22, 1940 :74 INVENTOR. Barron A. Procfor AT TORNEYJ Patented Nov. 17, 1942 RECORD SPINDLE DRIVING DEVICE Barton A. Proctor, Larchmont, N. 2., assignor to B. A. Proctor Company, Inc., New York, N. Y., a corporation of New York Application October 22, 1940, Serial No. 362,235

6 Claims.

This invention relates to a construction for securing a secure driving connection between the record of a sound recording and/or reproducing machine and the record spindle of the machine. The invention is illustrated in connection with a sound recording machine of the type disclosed in patent application No. 218,082, filed July 8, 1938, in the names of Barton A. Proctor and Ferdinand C. W. Thiede. The machine disclosed in the above application is provided with a vertical mounting spindle, upon which a thin, flexible disc record may be impaled, the record being driven by a pair of opposed feed rollers spaced from the spindle and which engage opposite faces of the record for rotating it and the spindle. The spindle is mounted upon a carriage and is connected to drive a feed screw which is also mounted upon the carriage and which cooperates with a half-nut, which is adapted to be engaged with or disengaged from the said screw under control of the operator. When the halfnut is engaged-with the feed screw, the record carriage is caused to be moved axially of the said screw and in turn to move the record spindle away from the record driving rollers, so that the zone of the record which extends radially between the spindle and the record driving rollers is maintained constantly under tension during the driving of the record. The stationary stylus of a recording or reproducing unit is mounted to act upon the record in the tensioned radial zone of the record which extends between the spindle and the point of contact of the record with the driving rollers and closely adjacent to the latter point.

' The record is supported for recording and reproducing upon a stationary support shaped like a turtle-back, suitable guides being provided for engaging the record near its outer margin and maintaining it in substantial conformity with the record support. The record disclosed is made in circular or disc form of a thin sheet of material, preferably of cellulose acetate which is transparent and has a thickness of approximately .005 inch. Both the upper and lower faces of such records are very smooth before recording therei A main object of the, present invention is the provision of a good driving connection between the record and record spindle of a machine of the type above described. This driving connec-- tion is also so arranged as to readily permit a record to be quickly attached to or removed from be rotated in unison with and at the same angular speed as the record.

In cases where the record is provided with a circular aperture adapted to loosely fit over the upper end of the record spindle, a further object of the invention is the provision of a trictional driving connection between the record and the spindle which will permit suiiicient power to be transmitted by the record to the spindle to drive the record carriage and cause it to move the record sidewise under the recording stylus without any slippage in the driving connection. In connection with suchva frictional driving connection, it is a cognate object of the invention to provide suitable means for maintaining the memher or members which effect such frictional driving connection continually under pressure during the rotation of the record.

A further object of the invention is the provision of a cap which fits over the upper end of the record spindle and which is provided with an automatic locking device which looks it in position on the spindle while maintaining a firm frictional driving connection between the record and the spindle.

Another object of the invention relates to the provision of a positive driving connection with the record spindle by means of a series of inwardly projecting teeth formed at the center of the record, which teeth fit into a series of similar shaped openings formed in the record spindle near its upper end, the teeth, however, being somewhat longer than the depth of the openings so that it is necessary to push downwardly on the record in order to secure it in proper position on the record spindle. The thinness and resiliency oi the record material permit the record to be pushed downwardly into position on the spindle, the resiliency of the material then causing the projecting teeth on the record to bias the center of it downwardly and maintain it in firm engagement with a flange formed on the record spindle.

In cases where it is desired to secure a positive driving connection between the record and spindle without applying any attachment over the end of the spindle to press downwardly on the record, it is a further object of the invention to secure such driving connection by means of a the record spindle, and to cause the spindle to its center portion to engage a flange formed on the record spindle so that the spindle is positively driven by the helical teeth thereon and the interfltting portions of the record.

Further objects'of the invention will become evident to those skilled in the art as the description thereof proceeds. For a better understanding of the invention, reference is made to the accompanying drawing, in which;

Fig. 1 is a longitudinal sectional view taken I through the center of a record and a record spindle and a driving connection therebetween embodying the invention, certain portions of a recording machine also being shown fragmentarily;

Fig. 2 is a longitudinal sectional view through the driving connection between 1 a record and record spindle showing a modified form of the invention;

Fig. 3 is a top fragmentary view showing the central portion of the record shown in Figs. 1 and 2;

Fig. 4 is a longitudinal sectional view of a driving connection between a record and record spindle showing another modified form of the invention;

Fig. 5 is a top view of the central portion of the record shown in Fig. 4 on a larger scale;

Fig. dis a front view partly in section of a driving connection between a record and record spindle showing another modified form of the invention; and

Fig. '7 is a sectional view showing the central portion of the record shown in Fig. 6.

Referring first to Figures 1 and 3, a record I of disc shape is shown as being driven by the upper and lower opposed feed rollers 2 and 3, a stylus 4 of a sound recording device 5 engaging the upper surface of the record substantially opposite the point of engagement therewith of a rotatable platen wheel 6, all as disclosed in the aforementioned application. Also as disclosed in said application, the record i is made of thin flexible sheet material and preferably of cellulose acetate which is transparent. It has been found that records of this material having a thickness of .005 inch are satisfactory for recording dictation from a microphone and also for reproducing the sound recorded. Before the re- A cording operation both faces of such a record are quite smooth and some difiiculty has been experienced in transmitting the rotation of such records to the vertical spindle of the recording machine, the rotation of which spindle causes the sidewise movement of the record carriage. and the movement of the center of the record away from the recording device 5. A portion of the record carriage is indicated at l, in which the vertical record spindle 8 is journaled for rotation. In the form of the invention shown in Figures 1 and 2. the record spindle 8 is provided .with an outwardly projecting flange 9 which may be formed integral with the spindle or may be secured thereto, as by means of a pin I0.

, The upper face of the flange 9 is provided with a facing II of a material which has a high coeflicient of friction with the material of the record as, for example, soft rubber. The record is provided at its center with a circular opening I2 as shown in Figure 3 adapted to loosely pass over the upper end of the spindle 8, the center portion of the record being held in firm engagement with the rubber facing II by means of a locking device L arranged for locking engagement with the upper end of the spindle 8. In the form of the invention shown in Figure 1, the locking device L comprises a hollow cap member I3 provided with a plurality of radial bores I4 adapted to loosely receive the balls I5 adapted for cooperative engagement with the curved surface It formed by cutting a groove in the spindle near its upper end. The balls I5 are biased inwardly toward the spindle 8 under the action of a pair of springs I1 provided at their lower ends with the followers I8 adapted to slide easily within the bores I4, the upper ends of the springs I'I being secured in position on the cap I3 by means of the screws I9.

The lower face of the cap I3 is preferably provided with a facing 20 of the same material as the facing II. Toprovide a proper driving connection'with the spindle 8, after placing the record I thereon with its lower face in contact with the facing II, the operator pushes the cap I3 down over the upper end of the record spindle and slightly compresses th yicldable facings II and 20 into the position shown in Fig. 1. The curved surface I8 defined by the groove in the spindle 8 is so disposed that under the action of the springs I1 a downwardly directed force is applied to the balls I5 which in turn causes the facing 20 to remain slightly compressed against the upper surface of the record. It has been found with the arrangement described that upon rotation of the record by the friction rollers 2 and 3, the spindle 8 is driven in unison with and at the .same'angular speed as the record I so that the successive turns of the sound track formed by the stylus 4 are uniformly spaced apart due to the translation of the record carriage I at a uniform speed.

To remove the record I from the spindle 8 after the recording is complete it is only necessary for the operator to withdraw the cap I3 from the end of the spindle 8 and lift the record off the spindle, after having first elevated the drive roller 2 and recording device 5 above the record by means of an operating lever (not shown) as disclosed in the aforementioned application.

In the form of the invention shown in Figure 2 the locking member L comprises the cap member I3 and a plate 2I whose lower surface is provided with the facing 20' of soft rubber or similar material. The cap I3 and plate H are biased apart under the action of a plurality of springs 22 whose ends are seated in aligned openings 23 and 24 provided in the cap I3 and a disc or plate 2 I. While only two springs 22 have been shown, it will be understood that three or more such springs may be provided, the springs being preferably spaced uniformly about the axis of the spindle 8. To prevent the disc 2I from becoming disengaged from the cap I3, the plate 2| is provided with one or more pins 25 adapted to loosely pass through corresponding bores 26 formed in the cap I3, each pin being provided with an enlarged head portion 21, as shown.

In effecting a driving connection with this form of the invention, after placing the record I on the spindle 8, the locking device L is pushed down over the upper end of the record spindle into the position shown in Fig. 2, the balls I5 becoming seated against the bottom of the curved surface I8 formed by the groove in the spindle and with the springs 22 compressed. Under the compression of the springs, the facings 20 and II are slightly compressed and held in firm frictional engagement with the upper and lower faces of the record.

To remove the record from the record spindle tor lifts the cap member I3 upwardly, the pins 25 causing the disc 2| to follow the cap off the end of the spindle, the enlarged head portion 21 on each pin 25 preventing the removal of the disc 2| from the cap l3.

In the form of the invention shown in Figs. 4 and 5, the record I is provided at its center with an irregular shaped aperture as shown in Fig. 5 to provide a series of inwardly projecting teeth 28 adapted to enter similar shaped recesses 29 provided in a sleeve 30 secured to the upper end of the record spindle 8', as by means of a pin 3|. Or the sleeve 30 may, if desired, be formed integral with the spindle 8. The recesses 29 are shallower than the teeth 28 on the record so that, asthe record is pushed down over the sleeve 30, the ends of the teeth 28 are bent upwardly slightly as indicated at 32 in Fig. 4. The resiliency of the record material permits it to be pushed on to the sleeve 30 and held against the flange 9'. with sufficient firmness so that the record I rotates thespindle 8 in unison therewith and without the record lifting from the position shown in Fig. 4 during the normal operation of the recording mechanism.

In the form of the invention shown in Fig. 6, the sleeve 30' is.grooved to provide a series of helical teeth 33. The record I" is provided at its center with a series of short teeth 34 adapted to fit between the helical teeth 33. The inclination of the teeth 33 is such that as the record I is driven in a direction indicated by the arrow, the teeth 33 exert a camming action on the record which causes its center portion to be urged downwardly into firm engagement with the flange 9" which acts as a stop and causes the spindle 8" to be driven in unison with the record. This locking action is not secured as soon as the record is placed on the upper end of the spindle 8" while it is stationary, but results from the rotation of the record in the direction shown by the arrow, there then being a constant tendency for the teeth 34 on the record to ride down the inclined teeth 33 and lock the two sets of teeth more firmly together besides causing the center portion of the record to be pressed downwardly into firm engagement with the flange 9" of the record spindle. At the same time the arrangement locks the record to the spindle and prevents it from lifting upwards away fromthe flange 9".

I have described what I believe to be the best embodiments of my invention. I do not wish,

however, to be confined to the embodiments shown, but what I desire to cover by Letters Patent is set forth in the appended claims.

I claim:

1. Means arranged to rotate the record spindle of a-sound translating device, comprising a thin disc record composed of resilient material, said record at its center being provided with a plurality of spaced inwardly projecting teeth and the top portion of the record spindle being providd with a plurality of grooves of similar shape to said teeth and the depth of the grooves being less than the length of the teeth on the record whereby the inner ends of the record teeth become bent upwardly and bias the,center portion of the record downwardly in response to the advancement of the record downwardly along the record spindle.

2. Means arranged to rotate the vertical record spindle of a sound translating device comprising,

a disc record provided at its center with a plurality of spaced-inwardly projecting teeth, a stop flange secured to said spindle and a plurality of helical cam surfaces formed on the upper end of the spindle, said cam surfaces being arranged to engage the teeth on the record and cause the center portion of the record to move axially of the spindle and downwardly into engagement with said stop flange in response to the rotation of the record.

3. Means arranged to rotate the vertical record spindle of a sound translating device comprising, a disc record provided at its center with a plurality of spaced inwardly projecting teeth, the upper end of the record spindle being provided with a. plurality of spaced helical teeth arranged for engagement with the teeth on the record and adapted to cam the center portion of the record downwardly in response to the rotation of the record and means for limiting the downward movement of the center portion of the record along the record spindle resulting from the camming action of the helical teeth.

4. In a sound translating device having a vertical record spindle, the combination of a thin flexible disc record, said record at its center being provided with a' plurality of symmetrically disposed inwardly projecting teeth; a supporting flange secured to the record spindle, said flange having a diameter only large enoughto engage and support. the record in the region immediately adjacent to said teeth and to permit more remote portions of the record to bend downwardly below the level of said supporting flange, a sleeve, a positive drive connection between said sleeve and the upper end of the record spindle, said sleeve being provided with a plurality of vertically elongated spaced teeth projecting outwardly between and arranged to engage theteeth on the record and the teeth on said sleeve cooperating 1 with those on the record to bias the center portion of the recordvdownwardly into firm engage ment with said supporting flange.

cal record spindle, the combination of adisc record said record at its center being provided with a plurality of inwardly projecting teeth, and the record spindle at its upper end-being provided with a plurality of elongated helically arranged teeth adapted to engage the teeth on the record and advance the center portion of the record downwardly along the record spindle in response to the rotation of the record, the teeth on the record cooperating with those on the record spindle to provide a positive driving connection between the record and record spindle.

6. A sound translating device as set forth in claim 5 in which a stop member is secured to the record spindle in position to be engaged by the center portion of the record to limit the down- .ward motion thereof along the record spindle.-

BARTON A; PROUIOR- 

